1. Field of the Invention
This application generally relates to digital rights management systems (hereafter referred to as DRM systems). Specifically, this application relates to the interoperability between different types of DRM systems and a trust model between those.
2. Description of the Related Technology
The proliferation of computing devices within our society has greatly increased in the past years. Where computing devices such as computers were previously used by scientist and engineers, now, a large percentage of society has access to or owns at least one computing device. In addition, many different types of computing devices have been created. Personal digital assistants (PDAs), smartphones, portable media players, and laptops have all become mainstream items.
Along with this huge growth of computing devices, the usage of digital media has grown as well. Books are now available in electronic format, movies and music are now available for download or for streaming, and photographs may now be accessed electronically. As with any media or copyrighted material, the authors, creators and distributors of such media wish to manage the access to the media. In response to the huge growth of digital media, DRM systems were created in the early '90s.
A digital rights management (DRM) system generally comprises access control and rights validation technologies to manage usage of digital media, in a way to offer a broad range of offerings and choices to meet the different needs of consumers. Publishers may want to limit the number of times a movie may be viewed, or to limit the number of times a particular media may be copied. There are generally three types of DRM system in use. The first is an identity-based DRM system, where access to digital media is allowed based upon verification of the identity of the user. For example, a user may enter a username and password to view the media. The second is a device-based DRM system, where access to digital media is allowed based on the validation of a unique identity of the device that is accessing the media. For example, the media will only play on a specific device. The third is a domain-based DRM system, where access to the digital media is allowed depending on whether or not a device is within a domain of identified devices. For example, all of the computers within a household may view the media. Even within the different types of DRM systems, different versions of DRM systems have been deployed in the marketplace.